1. Field of the Invention
The invention relates to a method and a device that can be used to obtain an element of information on depth in a picture-shooting device in order to enable the demarcation, in a picture, of the foreground zones from a background.
The invention can be applied notably to the field of television and cinema.
2. Description of the Prior Art
The television industry very often uses a special effects device enabling the extraction, from a colored background that is as uniformly colored as possible, of picture elements. This extraction can be done only if these picture elements do not contain the colors used in the background. These different devices are called chromakeys.
The limitations arising out of the need to have a uniform background color often make it impossible to achieve certain special effects, and it would be desirable to have information available on depth where such information is capable of establishing a very precise demarcation between the foreground subject and the backgrounds or backdrops, irrespectively of the variety of the colors with which they appear on the picture.